Fuel control system for diesel engines



Nov. 11', 1941. w. T. TABB FUEL CONTROL SYSTEM FOR DIESEL ENGINES Original Filed March 2, 1936 2 Sheets-Sheet 1 INVENTOR 6\ BY W v Wam Nov. 11, 1941. w. 'r. TABB 2,262,151

FUEL CONTROL SYSTEM FOR DIESEL ENGINES Original Filed March 2, 1936 2 Sheets-Sheet 2 f 51 11 139 137 I15 119 n 7% ;f 1515 I3] 153 123 r [/2 1/0 I 4 Q 127 1.2 1 INVENTOR 5 74 mm J W m L M mai 0M I ATTORNEYS Patented Nov. 11, 1941 FUEL CQNTROL SYSTEMFOR DIESEL ENGINES Warner T. Tabb, Brooklyn, N. Y., assignor to Eisemann Magneto Corporation,

Brooklyn,

N. 31., a corporation of New York I Continuation of application Serial No. 66,711, I March 2, 1936. This application February 12, 1943, Serial No. 378,505

3 Claims.

'I'h'n invention relates to means for controlling the speed of internal combustion engines and more particularly to means for governing the speed of Diesel engines by controlling the supp of fuel thereto, and it is an object of this inven- 121011 to provide a speed: responsive means for regulating the supply of fuel delivered to the engine cylinders by the fuel pump so as to maintain a predetermined uniform speed of the engine, and it is a further object of this invention to provide a device of the kind described wherein the speed responsive means is assembled within the casing of the fuel pump to produce an eflicient and reliable unit wherein the speed responsive means is protected from tampering or injury by the pump casing and a separate drive for the speed responsive means and linkage for operating the controlling valve or other means from the speed responsive means are eliminated.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

This application is a continuing or substitute application for my original application, Serial No. 66,711, filed March 2, 1936.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in ccifinlection with the accompanying drawings, in w c Fig. 1 is a central vertical sectional view of a Figs. 6 and 7 are partial views similar to Fig. 1 v of further modifications.

In Fig. 1 of the drawings this invention is shownapplied to a fuel pump for Diesel engines, such as is shown in U. S: Patent No. 2,166,876, issued July 18, 1939 in the name of E. M. Purdy.

Such a fuel pump comprises a casing consisting passage of the cam I4.

of an upper portion 5 and a lower portion 2, the upper portion being provided with a plurality of plunger chambers 4 symmetrically arranged about a bore or chamber 5 on the longitudinal axis of the casing, the chambers 4 having therein the followers 6 carrying the rollers 8 and engaging pump plungers III which are mounted for reciprocation in sleeves l2 fixed in the chambers 4. The followers 6 are operated in one direction by a cam I4 rotatably mounted in the lower portion 2 on ball-bearings l6 and driven by a flanged head [8 secured to a. drive shaft 20 which is driven in synchronism with the motor from any suitable rotating part thereof. A spring 22, confined between the casing portion I and a washer 24, fixed on the plunger It, holds each plunger it in engagement with the follower 6 and serves to retract the plunger and follower after Each plunger I0 is grooved, as at 24, intermediate its length and is provided with a transverse passage or port 26 at the groove 24 and which communicates with a longitudinally extending centrally located passage 28 which extends to the upper face of the pump plunger l0. Communicating with the bore of the sleeve l2 in which each pump plunger l0 reciprocates is a port or passage 30 in the casing portion I through which the fuel is supplied to the bore of the sleeve and a passage 32 which connects the bore of the sleeve with an annular passage 34 in a valve body or bushing 36 pressfitted in the central chamber 5, which passage 34 communicates with the fuel supply for the pump through a passage (not shown) in the casing portion l. The valve body 36 is also provided with ports 38 which communicate with the ports 30 in the casing portion l and with an annular passage 40 which communicates with the source of fuel supply and is connected by passages 42 to annular groove or passage 46. The ports 38 and the annular groove 48 are arranged to be connected by an annular groove 86 in a valve or member 48 which may be cylindrical and slidably mounted in acentral bore of the valve body 36.

The upper portion 50 of the valve body 36 is engaged by'a housing 52 secured to the'casing in the upper end of the housing 52 serve to limit the movement of the cam 58 in both directions.

'A pin 84 mounted in the upper portion 58 of the valve body 35 and engaging in an opening in the head of the valve 48 prevents rotation of the valve.

To the head I8, driven by the shaft 28, there is secured a sleeve 88 at the upper end of which there is fixed a pin "I8 on which arepivotally mounted the upper ends of weights." of a speed responsive means, the upper portions of the weights I2 being slotted to form arms which pass to opposite sides of the sleeve 58 to engage the ends of the pin I8. Links I4 lie in the slots in the weights I2 and are connected at their lower ends by pins 16 to the weights I2 and at their upper ends by pins .18 to a head 88 secured. by pin 8I to a sleeve 82 slidable in the sleeve 68 and slotted, as at 83, for the passage of the pin I8 on.which the weights I2 are mounted. Fixed in the upper end of the sleeve 82 is a plug 84 having a curved upper surface which engages with the lower end of a screw 86 threaded in the lower end of the valve 48 and adjustable so as to vary the position of the valve and the annular groove 86 with respect to the ports 38.

As in the construction schown in the. Purdy patent above referred to, reciprocation of the pump plungers I8 by the rotation of the cam I4 causes the fuel to be drawn into the bore of the sleeve I2 and forced therefrom past the usual check valve and out through the pipes 88 to the engine cylinders, the 'fuel being supplied from the source of supply through the annular recess or passage 48, passages 42 to the annular passage 48 and thence through the annular groove 86, passages 38 and ports -3|! to the bores of the sleeves I2. Movement of the plunger I8 forces the fuel through the pipe 88 to the engine cylinder until movement of the pump plunger causes the groove 24 onthe pump plunger to establish connection with the port 32, whereupon the pressure is vented from above the pump plunger through the longitudinal passage 28,- transverse passage 25 to the grooved portion of the pump plunger and through port 32 and annular passage 34 to the supply, cutting off the passage through the pipe 88 to the engine cylinders. The amount of fuel supplied to the bore of the sleeve I2 each time a pump plunger I8 is retracted will depend upon the extent of the open- 1 the weights I2 overcomes the resistance bf the spring 56, the valve 48 will be raised against the action of the spring 58 and the communication with ports 38 will be cut oil to a greater-or less extent, thereby varying the amount of fuel supplied to the bore of the sleeve I2v in accordance with the engine speed to maintain the desired speed of the engine: The engine speed at which the speed responsive means operates may. be

Fig. 3, the upper ends of the weights I2 and the lower face of the head 88 may be suitably 'shaped to provide camming surfaces 12 and 88 which will cooperate to raise the head 88 as the weights I2 are moved outwardly as shown in 10, Fig. 4.

In the construction shown in Fig. 1 the fuel is drawn into the bore of the sleeve I2 by a partial vacuum created by the retraction of the pump plunger and the amount of fuel thus 15 drawn in is controlled by the valve 48, but the invention is not limited to 'such a construction and, as shown in Fig. 5, it may be used in a construction where the fuel is supplied from an annular recess 34 which is in communication with the source of fuel supply, through the port 32 to the bore of the sleeve I2 when the pump plunger I8 is in its lowered position and a vent from the chamber above the pump plunger is controlled through passage 38 and annular groove 56 in the valve 48- as the pump plunger is moved upwardly, the groove establishing communication from the.passagej38 to passage 32 and thence to the annular passage34 in communication with the source of fuel supply. In this case, as in Fig.1, the valve 48 is operated by a speed responsive means to establish communication through the groove 66 to a greater or less extent betweenthe passages 38 and 32 in accordancewith the speed of the engine, permitting,

3 in this case, a greater or less venting of the varied by operating the shaft 58 and the earn 58 to vary the compression of the spring 56 and I in this manner vary the resistance of the valve 4 8 to operation by the governor weights.

In the modification shown in Fig. 3, in place of having the head 88 connected to the governor weights I2 by-links, the governor weights I2 are recessed at their upper ends and provided fluid from in front of the pump plunger I8 'as the pump plunger is raised to force the fluid to the engine cylinder in the usual manner and controlling the amount of fuel supplied to the engine cylinders. V

The invention is also applicable to fuel pumps of other types, such for instanceas that shown in U. S. Patent to Baur, No. 1,944,858, dated January 23, 1934, in which the control of the volume of fuel supplied to the engine cylinders by the pump plungers is by rotation of the pump plungers. In such a construction, as shown in Fig. 7, the pump plunger II 8 is mounted in a sleeve H2 and reciprocated in the usual manner by a cam operated follower I85 and a spring I22. The pump plunger atits upper end provided with a port I I5 which communicates with a recess II! in the face of the plunger having a helical upper wall II9 so positioned that by rotation of the pump plunger II8 communication through the recess II! and port H5 from the bore of the sleeve [I2 above the pump plunger to port I2I can be established at different points in the upward movement of the pump plunger II8.

To rotate the pump plunger H8 there is provided a sleeve I23 rotatably mounted on the outer face of the sleeve. H2 and slotted at its lower end, asat I25, to receive lugs I21 on a collar I23 fixed on the pump plunger 8. The sleeve I23 is provided with spiral gear teeth I3I which mesh with the similar teeth I33 on a gear I35 engaged on its lower side by the plug 84 of a speed responsive means, such as is shown in Fig. 1, and having projecting from its other face a stem I31 which extends through a plug I38 fixed in theupper end of the bore or chamber end of the stem I81 is fitted with a washer I 4! upon which is seated a spring I56 which may be adjusted, as in Fig. l, to vary the pressure exerted upon the washer by the spring and in this way vary the engine speed at which the speed responsive means operates the gear I35. The raising and lowering of the gear I35, through the connection of the teeth I33 thereon with the teeth I3I on the sleeves :23, will rotate the pump plungers III: so as to vary the point at which the recess I11 will establish communication with the port I H and in thisway vary the point at which the fuel under pressure above the pump plunger IIIi is vented to'the supply through port I2I, thus varying the amount of fuel supplied in accordance with the requirements of the engine.

In the modification shown in Fig. 6 there is provided a plurality' of chambers in which the pump plungers II) are mounted for reciprocation by the cam It as in the modification shown in Fig. 1. To the flanged extension I8 of the pump drive shaft 26 a nut I60 secures the impeller housing I62 of a speed responsive device, such as is shown in my US. Patent No. 1,818,825, issued August 11, 1931.

In the axial bore of the casing portion I there ismounted a valve body 36 having an annular passage I66 in communication with the source of fuel supply and passages I65 and I66 which communicate with the bores of the sleeves I'2 in which the pump plungers are mounted and with an axial bore in the valve body. In the axial bore in the valve body 36 is mounted a valve sleeve I68 having ports I10 adapted to establish communication between the passages I65 and the washer I92 there are provided flat springs I96 which engage in grooves in the valve sleeve I68 and in grooves in a ring I98 fixed in the bore in the housing, which springs may be arranged either to aid or oppose the action of the spiral spring I 16. A spring ring I99 secures the fiat springs I96 in position. Closingthe bore 5 of J'ects beyond the sleeve 204 and is engaged by I66. The structure of the valve sleeve and body is not claimed herein, the same being disclosed and claimed in my U. S. Patent No. 2,190,575, dated February 13, 1940. To the lower end of the valve I66 there is secured a spring housing I12 by means of a spring ring I14 and mounted within the housing I12 is a spiral spring I16 the outer turns of which have a sufiiciently large free diameter that when sprung into the housing they become frictionally secured to the hous ing and are held thereby except upon abnormal strains. The inner end of the spring I16 is bent inwardly and engaged in a slot in a sleeve I18 fixed on a shaft I80 which extends through the valve sleeve I68 and a cap I82 secured to the casing portion I so that means may be applied to the upper end thereof for rotating and holding the shaft I80 in adjusted position. The housing I12 projects below the spring I16 and at opposite points thereon lips or fingers I12 are pressed inwardly from the wall of the housing I12 forming shoulders which retain the spring I16 in the housing I12 and abutments which are engaged by a flat spring I84 mounted in a slot in the upper end of the stator shaft I86 of the speed responsive means. A pin I90 or other abutment projecting inwardly through the casing portion I is positioned to engage in the slot formed by pressing in the fingers or lips I12 and such pin may have an eccentric head'and be rotatably mounted in'the casing portion I so as adjustably to limit the movement of the spring housing in either or both directions.

The spring housing I12 bears against the valve of the valve in the opposite direction so that the ports I10 are maintained properly positioned with respect to the ports I65 and I66. Above the pins 208 fixed in the cover member 200 to limit the turning movement of the rod I80. The cap I82 secured by suitable bolts, not shown, to the housing portion I serves to hold the cover portion 200 in position, suitable packing and gaskets being provided between the various parts to prevent leakage therefrom.

As in the case of the device of my U. S. Patent No. 1,818,825, referred to above, operation of the device by the operation of the engine causes the stator to tend to rotate against the action of the spring I16, the tendency varying with the speed of rotation of the engine, and carrying with it the valve I68 so as to close to a greater or less extent communication between the ports I66 and I65, thereby restricting to a greater or less extent the fiow of fuel from the annular recess I64 through the ports I65, I10 and I66, to the chambers-above the pump plungers, thus governing the amount of fuel supplied to the chambers in accordance with the requirements of the engine.

While the type of speed responsive means shown in Fig. 6 is illustrated in connection with a valve operating as does the valve shown in Fig. 1, itisto be understood that it is not limited to such an arrangement but may be used in otherarrangements such as are. shown in Figs. 5 and 7.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it-is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as villustrative and not in a limiting sense. I

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a fuel control system for a Diesel engine or the like which has nozzles for injecting fuel into the engine cylinders, the combination with a pump provided with plungers for forcing fuel cyclically to said nozzles, said pump having a casing provided with an axial bore and a plurality of circumferentially disposed plunger bores and with sets of passages establishing communication between said axial: bore and said plunger bores whereby ingress and egress of fuel to the latter are afforded, of a valve member slidably disposed in the axial bore of such pump casing and provided with passage means controlling a selected set of fuel passages in the pump casing, said passage means being formed to balance any axial forces arising from the pressure of fuel passing therein, spring means for biasing said valve member in a desired position, a centrifugal governing unit disposed in said axial bore having its axis in line with said valve member and arranged to react against the pressure of said spring means for operating said valve member, and rotat'able means associated with the pump casing provided with an engine driven shaft and mechanically coupled for actuating said governing unit.

2. In a fuel control system for a Diesel engine or the like which has nozzles for injecting fuel into the engine cylinders, the combination with a pum provided with plungers for forcing fuel cyclically to said nozzles, said pump having a casing provided with an axial bore and a plurality of circumferentially disposed plungerbores and with sets of passages establishing communication between said axial bore and said plunger bores whereby ingress and egress of fuel to the latter are afiorded, of a valve member slidably disposed in the axial bore of such pump casing and provided with passage means controlling a selected set of fuel passages in the pump casing, said passage means meing formed to balance any axial forces arising from the pressure of fuel passing therein, a valve body fixedly disposed in said axial bore about said slidable valve member and provided with passages cooperating with fuel passages in the pump casing, spring means for biasing said valve member in a desired position, a centrifugal governing unit disposed in said axial bore having its axis in line with said valve member and arranged to react against the force resulting from pressure of said spring means for operating said valve member, means for adjusting said valve member relatively to said valve body and arranged to transmit the reaction of said governing unit to said valve member, and rotatable means associated with the pump casing provided with a shaft adapted to be driven by the engine and mechanically coupled for actuating said governing unit.

3. In a fuel control system for a Diesel engine or the like which has nozzles for injecting fuel into the engine cylinders; the combination with a pump provided with plungers for forcing fuel cyclically to said nozzles, said pump having a casing provided with an axial bore and a pluraln ity of circumferentiallylvdisposed plunger bores ing said governing unit.

and with sets of passages establishing communication between said axial bore and said plunger bores whereby ingress and egress of fuel to the latter are afforded, of a valve member slidably disposed in the axial bore of such pump casing and provided with passage means controlling aforce resulting from pressure of said spring means for operating said valve member, means for adjusting said valve member relatively to said valve body and arranged to transmit the reaction of said governing unit to said valve member, and rotatable eans associated with the pump casing provided with a shaft adapted to .be driven by the engin and mechanically coupled for actuat- WARNER T. TABB. 

